1. Field of the Invention
The present invention relates to musical sound generators used in electronic musical instruments, and more particularly to a musical sound generator which realizes a plurality of musical sound processing operations for the generation of a musical sound, using a single IC.
2. Description of the Related Art
Recently, generation of a musical sound which requires processing a large amount of data at high speed is performed by dedicated hardware called a sound source device. In the hard ware, a microcomputer processes control inputs (inputs from a keyboard and/or a console panel external control inputs such as MIDI, inputs from internal or external play memories, etc.,) to the musical instrument and transfers commands suitable for the sound source device to same.
As the number of required functions increases in the conventional musical sound generator, the number of operations and/or calculations also increases. As a result, a generalized method is to cause a plurality of LSIs to serve the corresponding functions to thereby achieve a desired synthetic function.
Recently, a sound source device itself is required to have various functions such as filtering musical sound waveform data (DCF) to change the tone of the musical sound, amplitude limitation (DCA), or even effect addition. As those functions are added, the number of operations/calculations increases, so that a plurality of LSIs are required to share the synthetic function, as mentioned above. Therefore, the use of a plurality of LSIs increases cost, complicates the design of delivery/reception of data between LSIs is complicated and invites limitations on the processing speed, disadvantageously.
Construction of a sound source device so as to produce musical effects only includes only addition of musical effects to a generated musical sound and outputting the result and cannot perform operations such as outputting only a musical sound to which no effects are added, the use of a separate external effect circuit provided without using the internal effect producing circuit, or mixing the internal effect output and the external effect circuit output and outputting the resulting effect.
That is, the conventional generator only performs operations for imparting internal effects to a musical sound and cannot obtain a wide variety of aspects of effect addition, disadvantageously.